Question

What is the correct sequence of assembly operation of peg-in-hole assembly? A. Hole crossing
B. Two-point contact
C. Approach
D. One-point contact

• A. A, C, B, D
• B. A, B, C, D
• C. C, A, D, B
• D. C, D, A, B

Hint:

Assembly progresses from free motion → single contact → constrained insertion.

Answer 1

The Correct Option is D

Concept: Peg-in-hole assembly is a classical problem in robotics and manufacturing involving constrained motion and contact transitions.

Step 1: Understand the stages.
The operation progresses through:
• Free motion (approach)
• Initial contact
• Increased constraint contact
• Full insertion

Step 2: First stage — Approach (C).

• Peg moves freely towards hole
• No contact exists

Step 3: Second stage — One-point contact (D).

• Peg touches rim of hole at one point
• Initial constraint begins

Step 4: Third stage — Hole crossing (A).

• Peg begins entering hole
• Alignment improves

Step 5: Fourth stage — Two-point contact (B).

• Peg contacts hole at two points
• Fully constrained during insertion

Step 6: Final sequence.
\[ C \rightarrow D \rightarrow A \rightarrow B \] Final Answer: \[ \boxed{C, D, A, B} \]